Before you dismiss this as a crazy investment strategy, consider that a recent study found it hasn’t done too badly, writes Steve Russolillo of The Wall Street Journal. Rutgers University professors Ivo Jansen and Andrei Nikiforov created a hypothetical trading strategy built around earnings announcements that demonstrated what Russolillo calls a “formidable track record.”
The study found that stocks exhibiting sharp moves relative to the market in the week before an earnings announcement tend to reverse sharply immediately after their report is released. The duo analyzed thousands of stock reactions from 1971 through 2012. If a stock (priced at $2 or above) had fallen by at least 5% five days before an earnings announcement, the strategy says to buy on the earnings date. Conversely, if the price had risen, it says to bet against it on the same date. The results showed profitability in 40 of the sample’s 42 years.
Russolillo writes, “the observation that stocks ‘mean-revert’ after sharp moves isn’t exactly new.” But the study found approximately 60% larger price reversals around earnings announcements than on days farther from a company’s quarterly report. With the third quarter reporting season nearly upon us, he says, “their research is worth considering, though perhaps not acting upon.”